This invention relates broadly to processes for making windowed bags for containing perishable and/or nonperishable goods and, more specifically, to methods of making a composite endless form which, in turn, can be used for making windowed, form, fill and seal bags, or containers, specifically used by form, fill and seal equipment, for example, such as ALLPAC F/F/S machines and BARTELT equipment.
A form, fill and seal machine can be supplied with an endless strip of paper-like material and bulk consumer product to automatically produce individual containers of product, such as tea, for retail sale. In this regard, in one mode of operation the endless strip of paper-like material is formed as a composite of paper and extruded polyethylene laminated on one side of the paper. The form, fill and seal equipment receives this endless composite, cuts the endless composite into individual bag forms, folds the individual bag forms into container bags with the polyethylene laminates overlapping at edges thereof and with materials being enclosed in the container bags, and heat-seals the polyethylene together at these edges. Thus, filled bags are formed by the form, fill and seal equipment and delivered to an outlet of the form, fill and seal equipment.
A problem which exists for the above described process is that container bags produced in this manner normally do not have windows therein through which the products contained therein can be viewed. In this regard, in many cases it is desirable that such bags have paper on an outer surface thereof onto which sales indicia can be printed, and a plastic, such as polyethylene, on an inner surface thereof for creating edge seams and for sealing the products therein. The paper is normally opaque. Although it is possible to use a transparent paper-like material instead of paper, which can then be made opaque at desired areas, such materials and the processing thereof are expensive and do not always meet the needs of the market. If one were to "blank" a window in the prior art paper laminate prior to polyethylene being extruded thereon, the molten polyethylene would pass through the window opening and contaminate equipment or otherwise cause problems. Similarly, it is not possible to cut the window after the molten polyethylene has been applied to the paper because the polyethylene material sticks to the paper.
It is therefore an object of this invention to provide a process for making an endless form for, in turn, making windowed bags for containing perishable and/or nonperishable goods.
Similarly, it is an object of this invention to provide a process and apparatus for making such an endless form which can be used by form, fill and seal equipment for making and filling windowed containers of retail goods.
At the same time, it is an object of this invention to provide a process and apparatus for making windowed form, fill and seal bags involving the use of an endless form having sales indicia printed thereon.